CLIP...
Sure, but (and it's a big but for me) - it enables files, incl executables, to be handled by non-OSX programs: I was horrified to see a bunch of Windows apps as available options, when going 'Open with' - there was no way I would let Windows code run free on my system.

it's doesn't "run free." When you click on a windows application, parallels starts and boots the appropriate VM to run that program. The Windows code runs in the VM, it's just that to make it easy to get to one application, Parallels let's you do with one click instead of having to start Parallels desktop, boot the VM and then launch the application. If you use Coherent mode, the Windows app opens in a window to make it LOOK like it's running natively, but it's not.